Windows

Problem

You want to place special characters (such as tab and newline) in a string variable.

Solution

In an expanding string, use PowerShell’s escape sequences to include special characters such as tab and newline.

PS >$myString = "Report for Today`n" PS >$myString Report for Today

Discussion

Aliteral string uses single quotes around its text, while an expanding string uses double quotes around its text.

Problem

You want to create a variable that holds text with newlines or other explicit formatting.

Solution

Use a PowerShell here string to store and work with text that includes newlines and other formatting information.

$myString = @" This is the first line of a very long string. A "here string" lets you to create blocks of text that span several lines. "@

Discussion

Problem

You want to create a variable that holds text.

Solution

Use PowerShell string variables to give you a way to store and work with text.

To define a string that supports variable expansion and escape characters in its definition, surround it with double quotes:

$myString = "Hello World"

To define a literal string (that does not support variable expansion or escape characters), surround it with single quotes:

$myString = 'Hello World'

Discussion

Problem

You want to find an easier or more compact way to represent a large if ... elseif ... else conditional statement.

Solution

Use PowerShell’s switch statement to more easily represent a large if ... elseif ... else conditional statement.

For example:

$temperature = 20 switch($temperature)

{ { $_ lt 32 } 32 { $_ le 50 } { $_ le 70 } default }
{ "Below Freezing"; break }{ "Exactly Freezing"; break }{ "Cold"; break }{ "Warm"; break }{ "Hot" }

Discussion

Problem

You want to control the conditions under which PowerShell executes commands or portions of your script.

Solution

Use PowerShell’s if, elseif, and else conditional statements to control the flow of execution in your script.

For example:

$temperature = 90

if($temperature le 0)

{

"Balmy Canadian Summer" } elseif($temperature le 32) {

"Freezing" } elseif($temperature le 50) {

"Cold" } elseif($temperature le 70) {

"Warm" } else {

"Hot" }

Discussion

Problem

You want to compare some data with other data and make a decision based on that comparison.

Solution

Use PowerShell’s logical operators to compare pieces of data and make decisions based on them.

Comparison operators:

eq, ne, ge, gt, lt, le, like, notlike, match, notmatch, contains, notcontains, is, isnot

Logical operators:

and, or, xor, not

Discussion

Problem

You want to add your own custom properties or methods to all objects of a certain type.

Solution

Use custom type extension files to add custom members to all objects of a type.

Discussion

Problem

You have an object and want to add your own custom properties or methods (members) to that object.

Solution

Use the AddMember cmdlet to add custom members to an object.

Discussion

Problem

You have a type of object and want to know detailed information about the methods and properties it supports.

Solution

The documentation for the .NET Framework (available on http://msdn.microsoft. com ) is the best way to get detailed documentation about the methods and properties supported by an object. That exploration generally comes in two stages:

1. Find the type of the object.

Problem

You have an instance of an object and want to know what methods and properties it supports.

Solution

The most common way to explore the methods and properties supported by an object is through the GetMember cmdlet.

To get the instance members of an object you’ve stored in the $object variable, pipe it to the GetMember cmdlet:

$object | GetMember GetMember –InputObject $object